Microchip Technology Inc
PIC18F2455 manufacturer

Microchip's USB page
Including information on the USB PICs as well as App notes and firmware examples

Mouser
The source of electronic components I am using

Digi-key
An excellent source for a wide range of electronic components, including 2N7000 transistors and PIC18F2455

WGsoft.de
Scan Master-ELM is the one I am using to test my adapters. I really like it..